Pasted valve bag with flexible elastic insert



y 1967 H. J. WINEGARD 3,318,511

PASTED VALVE BAG WITH FLEXIBLE ELASTIC INSERT Filed July 28, 1966 FIGI 2Sheets-Sheet l May 9, 1967 H. J. WINEGARD 3,

PASTED VALVE BAG WITH FLEXiBLE ELASTIC INSERT Filed July 28, 1966 2Sheets-Sheet 2 FIG? INVENTOR HOWARD J. WINEGARD ATTORNEY United StatesPatent 3,318,511 PASTED VALVE BAG WITH FLEXIBLE ELASTIC INSERT Howard J.Winegard, Trenton, N.J., assignor to Un on Camp Corporation, New York,N.Y., a corporation of Virginia Filed July 28, 1966, Ser. No. 568,607 9Claims. (Cl. 229-625) This invention relates to valve bags which areclosed by pasting at both ends except for a filling valve in one corner,and more particularly to a type of bag having a flexible insert in thevalve corner through which the bag is filled.

Paper bags having valved filling openings are in common use forpackaging bulk material, such as chemicals, cement, fertilizer, grain,feed, flour and the like. Such bags are made of a tough and strong paperor other fibrous material, and usually have walls comprising multi-plylayers of paper to increase their strength. Such bags are filled byinserting a spout through the filling opening and blowing the bulkmaterial therein. When the bag has been filled, the spout is withdrawnand the valve is automatically closed by the pressure of the material inthe bag against the valve. Since such valves have a tendency to leak andsift material, sleeves of flexible or limp paper have been inserted inthe valve to make a tighter closure of the filling opening and preventmaterial from sifting through the valve. Such valve sleeves are usuallymade of a single sheet of paper folded to form a tube with the oppositesides adhesively secured to the bag. Although such sleeves extendinginto the valve are an improvement from the standpoint of leakage, theleakage is not entirely prevented. Consequently when more expensivematerials are packaged in the bags, the sleeve is made longer andextends outward from the valve. After the bag has been filled, the freeor outer end of the sleeve is folded and tucked in between the overlyingflaps to provide an additional closure to prevent the material in thebag from seeping out. It is diflicu-lt to securely tuck in the end ofthe sleeve so that it will not be released during the transit of thefilled bag. Consequently such tuck-in sleeves have to be carefully andmanually tucked in by the workman who operates the filling machine, allof which substantially reduces the speed and increases the cost offilling the bags.

In order to provide a bag having the required strength to resist ruptureduring handling, many bags are being made with multi-ply walls. Such abag comprises a plurality of separate sheets positioned one inside theother and may have as many as six plies or layers of paper or acombination of paper and plastic. The multi-ply Walls have a substantialthickness that greatly reduces its flexibility. Furthermore, when theends of the bag are folded to form closure flaps, the overlapping foldsstill further increase the thickness and decrease the ability of thewall to flex, as well as forming irregular surfaces which are to beadhesively secured to each other. The difliculty of sealing theoverlapping flaps of such bags increases as the thickness of the wallincreases, which further reduces the flexibility of the wall andincreases the irregularity of the overlying surfaces to be pasted. As aresult, a bag having a multi-ply wall and a multi-ply valve is more aptto sift material therefrom and the probability of leakage increases asthe wall thickness increases.

An object of the present invention is to provide an improvedconstruction in a bag which insures a more perfect seal between thesurfaces of the overlapping flaps.

Another object is to provide a bag which has a valve that does notappreciably increase the thickness of the wall and does not decrease thewalls flexibility.

"ice

Another object is to provide a bag which has a standardized valve insertthat flexes to accept filling spouts of varying dimension.

Another object is to provide a bag which has a flexible valve insertthat does away with uneven bottom dimen- SlOIl.

Another object is to provide a bag which has a flexible valve insertthat returns to its original size upon removal of the filling nozzle.

Another object is to provide a bag which has a flexible valve insertthat provides a seal around the filling nozzle.

Another object is to provide a bag which has a flexible valve insertmade of elastic sheet material, such as rubber latex, milled rubber,polyvinylchloride, polyurethane, styrene-butadiene copolymer, or similarmaterial.

Another object is to provide a bag which has a flexible valve insertwhich is of simple and compact construction, economical to manufacture,and reliable in operation.

Another object is to provide a bag which has a flexible valve insertthat allows squaring out of the bag to use less paper.

Still another object is to provide a bag which has a flexible valveinsert that is especially effective in preventing fine materials fromsifting from the bag.

Other objects of the invention will in part be obvious and will in partappear hereinafter.

The invention accordingly comprises an article of manufacture possessingthe features, properties, and the relation of elements which will beexemplified in the article hereinafter described and the scope of theinvention which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention,reference should be had to the following detailed description taken inconnection with the accompanying drawing, in which:

FIG. 1 is a perspective view of a bag with the flexible valve insert inposition.

FIG. 2 is a plan view of the flexible valve insert.

FIG. 3 is a side view of the flexible valve insert.

FIG. 4 is a cutaway view of the flexible valve insert in place.

FIG. 5 is a cut-away view of the flexible valve in a bag being filled.

FIG. 6 is a plan view of a modified flexible valve insert made from alaminated sheet.

FIG. 7 is a cutaway view of the insert of FIG. 6 in place in the valve.

Referring to FIG. 1 of the drawings, there is shown a bag 10, preferablyformed of a heavy grade of kraft paper. It can also be constructed fromheavier or lighter material, depending on the requirements of the bag.As shown, the bag has side walls 12 and 13, portions of which are foldedinwardly to form an overlying end of conventional design having aninturned va-lve corner flap 11. The valve is indicated at 14 in FIG. 1and the insert is shown in greater detail in FIGS. 2 and 3 before itsinsertion in the valve corner.

As shown in FIGS. 2 and 3, the flexible valve 14 comprises a rectangularsheet of paper 15 having secured to its upper surface intermediate itsends at A, one end of a substantially rectangular section of rubberlatex sheet 16. The latex sheet 16 is secured on its opposite end to thebottom surface of a second paper sheet 17 at B, the second kraft sheet17 substantially overlapping the latex sheet 16 and the first papersheet 15. Latex sheet 16 is as wide as or wider than paper sheets 15 and17 in order to prevent leakage between the valve and the valve openingof the bag. Intermediate the secured ends of latex sheet 16 is anopening which may be a slit 18 having non-tearing ends 19, asillustrated, or an opening having a curvilinear contour, such as acircle or oval. While in my presheet to handle it during insertion inthe valve.

, size of the spout.

ferred embodiment I have utilized a rubber latex sh'eet,

Iany mate-rial that is strong enough to withstand tearing when thefilling spout is inserted in slit 18 and sufiiciently -stretchable tohave relatively full recovery to its original size when the spout isremoved can be utilized. In my preferred embodiment, I have found that arubber latex sheet of approximately five mils thick has the necessaryattributes. Other materials having the extensibility and recovery oflatex rubber will work equally well.

Paper sheet 15 is secured along its free overlapping end 7 to the top ofcorner flap 11, and latex sheet 16 is folded 4 tended that all mattercontained in the above description (or shown in the accompanyingdrawing) shall be interpreted as illustrative and not in a limitingsense.

back 180 along opening 18. This places sheet 17 in the position shown inFIG. 4. The end closure is formed by folding the end portions of sidewalls 12 and 13 on opposite sides of the bag inwardly toward each otherand securing them by glue to the upper surface of sheet 17, therebypositioning the valve in the bag as shown in FIGS. 1 and 4.

s In operation, as shown in FIG. 5, a filling spout 20 is.

inserted between sheets 15 and 17 and through stretchable opening 18 inthe elastic sheet 16. Material is passed through spout 20 which is incommunication with the.

inside of bag 10. When the bag is fill'ed arid the filling spout isremoved, the stretchable valve opening 18 reinsertion of the elasticsheet in the valve and to hold such sheet after it is inserted. It wouldbe quite difficult because of the softness and limpness of the elasticever, if that problem could be overcome, the elastic sheet alone wouldsufiice. Accordingly, a modification is shown in FIGS. 6 and 7, whichallows easy handling of the elastic sheet and saves the cost ofcombining the elastic sheets and the sheets of paper as heretoforedescribed FIG. 6 shows the elastic sheet 21 lightly laminated or coatedto a paper sheet 22. This laminated sheet has a fold line 23 in thecenter for centering the stretchable opening 18 in the .valve. Thelaminated sheet is inserted in the valve opening and secured at one endto the top of corner'fl-ap 11 and at the otherend to the folded endportions of the side walls 12 and 13. When the filling spout 20 isinserted in the stretchable opening 18 the paper will tear but theelastic sheet will stretch to the After the spout is removed the opening18 returns to its original dimension, as described in connection withthe other construction described above.

Since certain changes may be made in the'a'bove article, and ditferentembodiments of the invention could be made without departing from thescope thereof, it is in- It is also to be understood that the followingclaims are intended to cover all of the generic and specific fea- Vtures of the invention herein described, and all statements of the scopeof the invention which, as a matter of Ian g-uage, might be said to falltherebetween. 7

Having described my invention, what I claim as new and desire to secureby Letters Patent is:

1.'A pasted valve bag having 'side walls and an in- 'turned corner flap,aportion of said side Walls :being.

folded inwardly and overlapping said corner flap to form a valve openingin one corner, an elastic valve insert 'secured to and extendinginwardly between said overlap ping side walls and said corner flap, saidelastic valve insert having a stretchable opening in communication withthe interior of said bag for receiving a filling spout.

2. A pasted valve bag in accordance with claim 1, in which the elasticvalve insert comprises a first sheet of paper secured to said cornerflap, a second paper sheet secured to said overlapping side walls, asheet of elastic material at least as wide as the bag opening having arelatively small opening intermediate its ends, said elas tic materialhaving one end secured along the width of the upper surface of saidfirst paper sheet and its oppo-' site end secured along the width of thelower surface of said second paper sheet, whereby said opening communiecates with the interior of said bag.

7 3. A pasted valve bag in accordance with claim 1 in 7 which theelastic material is rubber latex.

4. A pasted valve bag in accordance with claim 1 in lwhich the elasticvalve insert comprises styrene-butadiene out that the sheets 15 and 17primarily serve to permit Howcopolymer mounted on a paper sheet.

-5. A pasted valve bag in accordance with claim 1 in which the openingin theelastic material has a curvilinear contour.

6. A pasted valve bag in accordance with claim 1 in' which the elasticvalve insert is secured to said bag 'by an adhesive.

7. A pasted valve bag in accordance with claim 2 which the sheet ofelastic material is secured to said paper sheets by a fusion bond.

8. A pasted valve bag in accordance with claim 1 in overlapping sidewalls and said corner flap.

References Cited by the Examiner V UNITED STATES PATENTS 946,318 1/1910Bates 229 62.s 1,476,560 12/1923 Witmer 229-625 2,338,254

1/1944 Miller 22962.S

JOSEPH R. LECLAIR, Primary Examiner. D. BOCKENEK, Assistant Examiner,

1. A PASTED VALVE BAG HAVING SIDE ALLS AND AN INTURNED CORNER FLAP, APORTION OF SAID SIDE WALLS BEING FOLDED INWARDLY AND OVERLAPPING SAIDCORNER FLAP TO FORM A VALVE OPENING IN ONE CORNER, AN ELASTIC VALVEINSERT SECURED TO AND EXTENDING INWARDLY BETWEEN SAID OVERLAPPING SIDEWALLS AND SAID CORNER FLAP, SAID ELASTIC VALVE INSERT HAVING ASTRETCHABLE OPENING IN COMMUNICATION WITH THE INTERIOR OF SAID BAG FORRECEIVING A FILLING SPOUT.